I've looked at the problem recently. The flush handles travel through 180 degrees but operate in only 90 degrees. You'd have to see it in action to see what I mean but basically the extra movement of the handle allows it to return to the flush position while the mechanism itself only operates in 90 degrees. However, that 90 degrees is not translated directly to the gear that the stock door handle uses. Instead, it is applied through an arm and pushrod to one of the stock rods and operates the entire mechanism by pushing that rod back and forth. The most direct way to alter it would be to (just
) change the throw of the flush handle mechanism by lengthening its arm. That is not that easy to begin with, in the space of the door (I looked into machining a new rotator cup as opposed to trying to attach a longer arm) and leads to other potential problems, such as increased forces on the pushrods and also greater required force on the exterior handle to operate the mechanism.
Another way to do it would be to change the flush mechanism so its pushrod does not drive one of the stock rods directly but instead drives a gear meshed with the stock gear. This gear could be sized to give whatever throw in the stock system you require. It still has the potential to create higher operating forces at the flush handle but the gears could be housed so that they could take the internal forces much better than the current setup.
In the end, I have decided that I will go with plan C. I'm going to use the flush mechanism but modify it so it attaches to the stock gear instead of one of the driving rods. I'm planning an arm that acts like the exterior handle but is inside the door instead of outside. I may size the arm to increase the throw to greater than 90 degrees and am planning to use the angled pins and guides plus, if I can get them separately, the new door guides that allow greater travel without the pins falling inside the door. I'm going to do without the rest of the kit, however. Not because I don't think it's a great idea or design but I think it won't be needed. That's because I am going to use microswitches (automotive sealed ones) to detect if the door is closed or not. This way I won't have anything external to the door. I know people have had problems with idiot lights, both due to the magnetic sensors not being up to the job and visibility problems on the panel. Microswitches will solve the first problem and the Vertical Power system I will be using can annunciate, so that should solve the latter ... at least until I go deaf.
Please understand that I am not saying not to use Sean's kit. It's an awesome design and definitely best of breed. If he ever figures out a door-internal version, I am sold. I also think his pins and guides are top-notch and agree with his advice that the angled ones are better than the bullet ones. Actually, if there's anything I find klunky, it's the way those beautifully machined flush latches from iflyrv10 mate to the stock mechanism but I hope they will take this as constructive criticism and make a more integrated version. As it is, their solution is more than adequate.
If you want to think this out yourself, the instructions for the flush handles are available online at iflyrv10 (except for the internal mechanism of the handles, but I have examined them and will swear to you that you won't change them to 180 degrees without major machining from new stock). Likewise for Sean's kits, there's Scott's excellent report on his installation with great pictures. Maybe a real engineer
will come up with better ideas than I had; it couldn't be hard.